With a blank ruler (without marks) of exactly 13 cm you can only measure 13 cm. Now you are allowed to set 4 marks so that you may read off all full centimetre values from 1 to 13 cm directly from the ruler.Where must these 4 marks be?Much harder question:The blank ruler has a length […]

My computer has been up to its usual tricks again. I wanted to know the population of some major countries and here are the results:USA 1,30,000England 4,10,000France 3,40,000Peru 2,00,000Brazil 3,40,000Greece 3,00,000Japan 2,70,000How many people were listed as living in Tibet? Answer270,000 people.Each vowel is worth 3 and each consonant is worth 7; these are added

Jeff has a bunch of coins. Figure out how many coins he has using only these facts:He puts an equal amount in each of 9 bags and has none left over.He puts an equal amount in each of 6 bags and has none left over.He puts an equal amount in each of 5 bags and

Glenn’s step is 4 fifths of that of his father’s and he walks 30 steps in a minute.Glenn’s sister, Melanie has a step which is 3 quarters of Glenn’s and walks 25 steps in a minute.Glenn’s mother has a step which is twice the size of Melanie’s and walks 20 steps in a minute, but

A farmer wants to sell sheep at a fair which lies on the other side of the hill under which he lives. In order to get there in time, he needs to travel at an average speed of 60km/h. The road is 10km up the hill and 10km down the hill. However, his car can

Dad wants one-cent, two-cent, three-cent, five-cent, and ten-cent stamps. He said to get four each of two sorts and three each of the others, but I’ve forgotten which. He gave me exactly enough to buy them; just these dimes. How many stamps of each type does Dad want? A dime is worth ten cents. AnswerThe

You have a group of eighty-two men. Some of the men are tall, the number of the medium-height men is double that of the tall men and the number of the short men is triple that of the medium-height men and one man is very tall. You know that all tall men are bald but

A bookworm eats from the first page of encyclopaedia number 1 to the last page of encyclopaedia number 5. The bookworm eats in a straight line. Each encyclopaedia consists of 400 pages. Each leaf is 0.01 inch thick and each cover is 0.25 inch thick. What distance does the bookworm eat through? AnswerThe bookworm nibbles

Peter had 144 books and donated them to four schools. When Peter checked the number of books given to each school, he found out that the difference of the number of books between School A and School B was 4; between School B and School C was 3; between School C and School D was

The Principal of Jimbo’s school interviewed 30% of the 8th graders at recess about the food fight yesterday. The Assistant Principal grabbed 40% of the 8th graders at lunchtime to investigate the disappearance of all of the blackboard erasers. Fortunately for Jimbo, he was in the 50% of the 8th graders that escaped without an

Two cars circumnavigate the world. Time is kept as they pass each other, travelling in opposite directions at the same speed of 70 miles per hour. The only difference is that one car is travelling on the surface of the planet, while the other is on a roadway 15 feet above ground.Assuming the world is

Two years ago, a problem surfaced at the Romankachi Pharmaceuticals Ltd. – one of the many companies belonging to the huge Romankachi conglomerate.We were devising a three digit id (non-zero first digit) for the employees such that no two employees can have id’s that are identical when written in the reverse order. For example, 123

Fred took a ball that has a 13-inch diameter and drilled a circular hole through the centre of it. The hole was 5 inches wide, but how deep is it? Answer12 inches.To solve this one, we can use the work of Pythagoras. If we draw the ball and hole from the side, they look like

A frog fell into a well that was 12 feet deep. It could jump three feet, but every time it did, it would fall back two feet. How many times did the frog have to jump before it got out of the well? Answer10… on the 10th jump it reached 12 feet and was out.

In the legendary country of MADADIA there was an unscrupulous factory owner called “Nastee O’Baskit”. He paid his workers only £2 a day, but would fine them £3 a day if he caught them sitting down. After 30 working days (not including weekends) one of his workers received his wage packet, which was empty. When